target/linux/mvebu/patches-3.8/008-mmc_mvsdio_implement_a_device_tree_binding.patch

   1 This patch adds a simple Device Tree binding for the mvsdio driver, as
   2 well as the necessary documentation for it. Compatibility with non-DT
   3 platforms is preserved, by keeping the platform_data based
   4 initialization.
   5
   6 We introduce a small difference between non-DT and DT platforms: DT
   7 platforms are required to provide a clocks = <...> property, which the
   8 driver uses to get the frequency of the clock that goes to the SDIO
   9 IP. The behaviour on non-DT platforms is kept unchanged: a clock
  10 reference is not mandatory, but the clock frequency must be passed in
  11 the "clock" field of the mvsdio_platform_data structure.
  12
  13 Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  14 ---
  15  .../devicetree/bindings/mmc/orion-sdio.txt         |   17 ++++++
  16  drivers/mmc/host/mvsdio.c                          |   60 +++++++++++++++-----
  17  2 files changed, 62 insertions(+), 15 deletions(-)
  18  create mode 100644 Documentation/devicetree/bindings/mmc/orion-sdio.txt
  19
  20 --- /dev/null
  21 +++ b/Documentation/devicetree/bindings/mmc/orion-sdio.txt
  22 @@ -0,0 +1,17 @@
  23 +* Marvell orion-sdio controller
  24 +
  25 +This file documents differences between the core properties in mmc.txt
  26 +and the properties used by the orion-sdio driver.
  27 +
  28 +- compatible: Should be "marvell,orion-sdio"
  29 +- clocks: reference to the clock of the SDIO interface
  30 +
  31 +Example:
  32 +
  33 +       mvsdio@d00d4000 {
  34 +               compatible = "marvell,orion-sdio";
  35 +               reg = <0xd00d4000 0x200>;
  36 +               interrupts = <54>;
  37 +               clocks = <&gateclk 17>;
  38 +               status = "disabled";
  39 +       };
  40 --- a/drivers/mmc/host/mvsdio.c
  41 +++ b/drivers/mmc/host/mvsdio.c
  42 @@ -21,6 +21,8 @@
  43  #include <linux/irq.h>
  44  #include <linux/clk.h>
  45  #include <linux/gpio.h>
  46 +#include <linux/of_gpio.h>
  47 +#include <linux/of_irq.h>
  48  #include <linux/mmc/host.h>
  49  #include <linux/mmc/slot-gpio.h>
  50
  51 @@ -683,17 +685,17 @@ mv_conf_mbus_windows(struct mvsd_host *h
  52
  53  static int __init mvsd_probe(struct platform_device *pdev)
  54  {
  55 +       struct device_node *np = pdev->dev.of_node;
  56         struct mmc_host *mmc = NULL;
  57         struct mvsd_host *host = NULL;
  58 -       const struct mvsdio_platform_data *mvsd_data;
  59         const struct mbus_dram_target_info *dram;
  60         struct resource *r;
  61         int ret, irq;
  62 +       int gpio_card_detect, gpio_write_protect;
  63
  64         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  65         irq = platform_get_irq(pdev, 0);
  66 -       mvsd_data = pdev->dev.platform_data;
  67 -       if (!r || irq < 0 || !mvsd_data)
  68 +       if (!r || irq < 0)
  69                 return -ENXIO;
  70
  71         r = request_mem_region(r->start, SZ_1K, DRIVER_NAME);
  72 @@ -710,7 +712,35 @@ static int __init mvsd_probe(struct plat
  73         host->mmc = mmc;
  74         host->dev = &pdev->dev;
  75         host->res = r;
  76 -       host->base_clock = mvsd_data->clock / 2;
  77 +
  78 +       /* Some non-DT platforms do not pass a clock, and the clock
  79 +          frequency is passed through platform_data. On DT platforms,
  80 +          a clock must always be passed, even if there is no gatable
  81 +          clock associated to the SDIO interface (it can simply be a
  82 +          fixed rate clock). */
  83 +       host->clk = clk_get(&pdev->dev, NULL);
  84 +       if (!IS_ERR(host->clk))
  85 +               clk_prepare_enable(host->clk);
  86 +
  87 +       if (np) {
  88 +               if (IS_ERR(host->clk)) {
  89 +                       dev_err(&pdev->dev, "DT platforms must have a clock associated\n");
  90 +                       ret = -EINVAL;
  91 +                       goto out;
  92 +               }
  93 +
  94 +               host->base_clock = clk_get_rate(host->clk) / 2;
  95 +               gpio_card_detect = of_get_named_gpio(np, "cd-gpios", 0);
  96 +               gpio_write_protect = of_get_named_gpio(np, "wp-gpios", 0);
  97 +       } else {
  98 +               const struct mvsdio_platform_data *mvsd_data;
  99 +               mvsd_data = pdev->dev.platform_data;
 100 +               if (!mvsd_data)
 101 +                       return -ENXIO;
 102 +               host->base_clock = mvsd_data->clock / 2;
 103 +               gpio_card_detect = mvsd_data->gpio_card_detect;
 104 +               gpio_write_protect = mvsd_data->gpio_write_protect;
 105 +       }
 106
 107         mmc->ops = &mvsd_ops;
 108
 109 @@ -750,21 +780,14 @@ static int __init mvsd_probe(struct plat
 110         } else
 111                 host->irq = irq;
 112
 113 -       /* Not all platforms can gate the clock, so it is not
 114 -          an error if the clock does not exists. */
 115 -       host->clk = clk_get(&pdev->dev, NULL);
 116 -       if (!IS_ERR(host->clk)) {
 117 -               clk_prepare_enable(host->clk);
 118 -       }
 119 -
 120 -       if (gpio_is_valid(mvsd_data->gpio_card_detect)) {
 121 -               ret = mmc_gpio_request_cd(mmc, mvsd_data->gpio_card_detect);
 122 +       if (gpio_is_valid(gpio_card_detect)) {
 123 +               ret = mmc_gpio_request_cd(mmc, gpio_card_detect);
 124                 if (ret)
 125                         goto out;
 126         } else
 127                 mmc->caps |= MMC_CAP_NEEDS_POLL;
 128
 129 -       mmc_gpio_request_ro(mmc, mvsd_data->gpio_write_protect);
 130 +       mmc_gpio_request_ro(mmc, gpio_write_protect);
 131
 132         setup_timer(&host->timer, mvsd_timeout_timer, (unsigned long)host);
 133         platform_set_drvdata(pdev, mmc);
 134 @@ -776,7 +799,7 @@ static int __init mvsd_probe(struct plat
 135                            mmc_hostname(mmc), DRIVER_NAME);
 136         if (!(mmc->caps & MMC_CAP_NEEDS_POLL))
 137                 printk("using GPIO %d for card detection\n",
 138 -                      mvsd_data->gpio_card_detect);
 139 +                      gpio_card_detect);
 140         else
 141                 printk("lacking card detect (fall back to polling)\n");
 142         return 0;
 143 @@ -855,12 +878,19 @@ static int mvsd_resume(struct platform_d
 144  #define mvsd_resume    NULL
 145  #endif
 146
 147 +static const struct of_device_id mvsdio_dt_ids[] = {
 148 +       { .compatible = "marvell,orion-sdio" },
 149 +       { /* sentinel */ }
 150 +};
 151 +MODULE_DEVICE_TABLE(of, mvsdio_dt_ids);
 152 +
 153  static struct platform_driver mvsd_driver = {
 154         .remove         = __exit_p(mvsd_remove),
 155         .suspend        = mvsd_suspend,
 156         .resume         = mvsd_resume,
 157         .driver         = {
 158                 .name   = DRIVER_NAME,
 159 +               .of_match_table = mvsdio_dt_ids,
 160         },
 161  };
 162